Glass plate with glass frit structure

ABSTRACT

A light emitting device includes: a first substrate; a second substrate; a light emitting unit interposed between the first substrate and the second substrate; and a sealing material bonding the first substrate to the second substrate and sealing the light emitting unit. The sealing material comprises V +4 . In addition, a glass frit, a composition for forming a sealing material, and a method of manufacturing a light emitting device using the composition for forming a sealing material are provided to obtain the light emitting device. The sealing material of the light emitting device can be easily formed by coating and irradiation of electro-magnetic waves, so that manufacturing costs are low and deterioration of the light emitting unit occurring when sealing material is formed can be substantially prevented. The sealing material has good sealing properties and thus a light emitting device including the sealing material has a long lifetime.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This application is a divisional application of and claims priority toU.S. application Ser. No. 11/742,078, now U.S. Pat. No. 7,871,949, filedApr. 30, 2007 which claims the benefit of Korean Patent Application No.10-2007-0001681, filed on Jan. 5, 2007, in the Korean IntellectualProperty Office, the disclosure of both of which is incorporated hereinin its entirety by reference.

BACKGROUND

1. Field

The present invention relates to a glass frit for use in packaging lightemitting display devices.

2. Description of the Related Art

Electronic devices, such as an organic light emitting device, anelectron emission device, or a display panel, deteriorate due to thepermeation of water and/or oxygen therein. As a result, such electronicdevices are necessarily encapsulated to operate stably and to have along lifetime.

For such encapsulation of the electronic devices, a metallic can orglass is processed into a cap shape having a groove, and then awater-drying agent that absorbs water is loaded in the groove in a formof a powder, or the water-drying agent is processed into a film and thenattached using a double-sided tape.

Japanese Patent Laid-open Publication No. 9-148066 discloses an organiclight emitting display device including a stack structure of an organiclight emitting layer formed of an organic compound interposed between apair of facing electrodes, wherein the stack structure of the organiclight emitting layer is encapsulated from external air by a sealingcontainer, and an alkali metal oxide acting as a drying agent isdisposed within the sealing container. However, the organic lightemitting display device is thick due to the formation of the sealingcontainer. In addition, even when the drying agent absorbs water andstays in a solid state, the solid drying agent becomes opaque, which isnot suitable for a front emission type display device.

U.S. Pat. No. 6,226,890 discloses an organic light emitting device usinga water absorbing layer which is prepared using a water absorbing agentincluding a solid particle having a particle size of 0.1-200 μm and abinder.

However, organic light emitting devices manufactured using theseencapsulating methods do not achieve a desired lifetime. Accordingly,there is a need to improve such encapsulating methods.

SUMMARY

One aspect of the invention provides a glass fit comprising vanadium inthe form of V⁺⁴. The glass fit has a light transmittance of about 50% orless for light with the wavelength of 810 nm.

The glass frit may further comprise at least one ion selected from thegroup consisting of V⁺⁵, Ba⁺², Zn⁺², Te⁺⁴, Fe⁺³, Cu⁺², Nd⁺², K⁺¹, Sb⁺³,P⁺⁵, Ti⁺², Al⁺³, B⁺³, W⁺⁶, Sn⁺², Bi⁺³, Ca⁺², Si⁺⁴, Zr⁺⁴, and Mg⁺². Theglass frit may still further comprise V⁺⁵, Ba⁺², Zn⁺², and Te⁺⁴. Atleast part of V⁺⁴ is formed by reducing V⁺⁵. The glass fit may furthercomprise at lease one reducing agent selected from the group consistingof Sn, Al, Mg, Cu, and Zn.

The light transmittance may be about 30% or less. The lighttransmittance may be about 20% or less. The glass frit may have a lighttransmittance of about 40% or less for light with a wavelength fromabout 650 nm to about 1000 nm. The glass frit may have a lighttransmittance of about 30% or less for light with a wavelength fromabout 650 nm to about 1000 nm. The glass fit may have a lighttransmittance of about 20% or less for light with a wavelength fromabout 650 nm to about 1000 nm.

Another aspect of the invention provides a glass frit comprisingvanadium in the form of V⁺⁴. The glass frit has a light transmittance ofabout 50% or less for light with the wavelength of 810 nm.

The glass frit may further comprise at least one ion selected from thegroup consisting of V⁺⁵, Ba⁺², Zn⁺², Te⁺⁴, Fe⁺³, Cu⁺², Nd⁺², K⁺¹, Sb⁺³,P⁺⁶, Ti⁺², Al⁺³, B⁺³, W⁺⁶, Sn⁺², Bi⁺³, Ca⁺², Si⁺⁴, Zr⁺⁴, and Mg⁺². Theglass frit may still further comprise V⁺⁵, Ba⁺², Zn⁺², and Te⁺⁴. Atleast part of V⁺⁴ is formed by reducing V⁺⁵. The glass frit may furthercomprise at lease one reducing agent selected from the group consistingof Sn, Al, Mg, Cu, and Zn.

The light transmittance may be about 30% or less. The lighttransmittance may be about 20% or less. The glass frit may have a lighttransmittance of about 40% or less for light with a wavelength fromabout 650 nm to about 1000 nm. The glass fit may have a lighttransmittance of about 30% or less for light with a wavelength fromabout 650 nm to about 1000 nm. The glass frit may have a lighttransmittance of about 20% or less for light with a wavelength fromabout 650 nm to about 1000 nm.

According to still another aspect of the invention, the glass frit maybe in the form a powder, a paste, or a sintered body. The sintered bodymay be dark, and substantially translucent. The V⁺⁴ may exist in theglass frit in an amount from about 0.0001 wt % to about 10 wt %. V⁺⁴ mayexist in the glass fit in an amount from about 0.0001 wt % to about 5 wt%, from about 0.0005 wt % to about 5 wt %, from about 0.001 wt % toabout 5 wt %, from about 0.01 wt % to about 5 wt %, from about 0.01 wt %to about 1 wt %, or from about 0.1 wt % to about 1 wt %. V⁺⁴ may existin the glass frit in an amount of about 0.0001 wt %, about 0.0005 wt %,about 0.001 wt %, about 0.005 wt %, about 0.01 wt %, about 0.05 wt %,about 0.1 wt %, about 0.5 wt %, about 1 wt %, about 5 wt %, about 10 wt%, or about 50 wt %. V⁺⁴ may exist in the glass fit in an amount withina range formed by two of the foregoing numbers.

According to still another aspect of the invention, the V⁺⁴ may existmore on a surface of the sintered body than the interior thereof. Thesintered body may be formed by baking a paste form of the glass frit.The sintered body may further be heated by further illuminating a laserbeam thereon. The presence of the V⁺⁴ in the glass frit composition maybe detectable by X-ray Photoelectron Spectroscopy (XPS).

The glass frit may further comprise at least one filler selected fromthe group consisting of a zirconium-tungsten-phosphate based filler, azirconium-phosphate based filler, a zirconium-based filler, aneucrytite-based filler, a cordierite-based filler, alumina, silica, zincsilicate, and aluminum titanate. The filler may have an average particlediameter from about 0.1 μm, to about 30 μm. A thermal expansioncoefficient of the composition may be in the range from about 25×10⁻⁷/°C., to about 95×10⁻⁷/° C.

The glass frit may further comprise at least one resin selected from thegroup consisting of an acryl-based resin, a methacryl-based resin, avinyl-based resin, an epoxy-based resin, a urethane-based resin, and acellulose-based resin, and further comprising at least one solventselected from the group consisting of terpinol, dihydro terpinol,butylcarbitolacetate, butyl carbitol, and 2,2,4-trimethyl-1,3-pentadiolmonobutyrate.

According to still another aspect of the invention, a glass frit devicemay comprise a glass plate comprising a surface; and a glass fritcomposition, and the glass frit may form a closed loop on the surface ofthe glass plate. The sintered body may have light transmittance of 40%or less for light at a wavelength 810 nm. The sintered body may havelight transmittance of 40% or less for light at a wavelength from about650 nm to about 1000 nm.

According to still another aspect of the invention, a method ofmanufacturing a glass frit device comprises: providing the glass platecomprising the surface; forming a closed loop structure of a pastecomposition; heating the closed loop structure so as to form the glassfrit forming a closed loop on the surface, and the glass frit comprisesV⁺⁴ and has a light transmittance of about 50% or less for light at thewavelength of 810 nm.

According to still another aspect of the invention, a method of making adisplay device comprises: providing the glass frit device; providing anintermediate device comprising a substrate and an array of lightemitting devices formed on the substrate; arranging the glass fritdevice and the intermediate device such that the glass frit isinterposed between the glass plate and the substrate, and that the glassfrit contacts the substrate wile surrounding the array; and applyinglaser onto the glass fit so as to bond the glass frit to the substrate.The transmittance of the laser may be about 40% or less.

According to still another aspect of the invention, a display devicecomprises: a first substrate; a second substrate; an array of lightemitting devices interposed between the first substrate and the secondsubstrate; and the glass frit, and the glass frit is interposed betweenand bonds the first substrate to the second substrate. The lightemitting device may comprise an organic light emitting diode.

The glass frit may have a light transmittance of about 50% or less forlight with a wavelength of 810 nm or from about 650 nm to about 1000 nm.The glass frit may have a light transmittance of about 55% or less,about 54% or less, about 53% or less, about 52% or less, about 51% orless, about 50% or less, about 49% or less, about 48% or less, about 47%or less, about 46% or less, about 45% or less, about 44% or less, about43% or less, about 42% or less, about 41% or less, about 40% or less,about 39% or less, about 38% or less, about 37% or less, about 36% orless, about 35% or less, about 34% or less, about 33% or less, about 32%or less, about 31% or less, about 30% or less, about 29% or less, about28% or less, about 27% or less, about 26% or less, about 25% or less,about 24% or less, about 23% or less, about 22% or less, about 21% orless, about 20% or less, about 19% or less, about 18% or less, about 17%or less, about 16% or less, about 15% or less, about 14% or less, about13% or less, about 12% or less, about 11% or less, about 10% or less,about 9% or less, about 8% or less, about 7% or less, about 6% or less,about 5% or less, about 4% or less, about 3% or less, about or 2%, for alight with a wavelength of 810 nm or from about 650 nm to about 1000 nm.The light transmittance has ranges formed by two of the forgoingnumbers.

One aspect of the present invention provides a light emitting devicehaving a long lifetime and using a sealing material having good sealingproperties.

Another aspect of the present invention also provides a glass fit and acomposition for forming a sealing material to manufacture the lightemitting device, and a method of manufacturing a light emitting device.

According to an aspect of the present invention, there is provided aglass frit including V⁺⁴. According to another aspect of the presentinvention, there is provided a composition for forming a sealingmaterial including a glass frit having V⁺⁴. The composition for forminga sealing material may further include a zirconium-tungsten-phosphatebased filler. According to another aspect of the present invention,there is provided a composition for forming a sealing material includinga glass frit having V⁺⁵ and a zirconium-tungsten-phosphate based filler.According to another aspect of the present invention, there is provideda light emitting device including: a first substrate; a secondsubstrate; a light emitting unit interposed between the first substrateand the second substrate; and a sealing material bonding the firstsubstrate to the second substrate and sealing the light emitting unit,wherein the sealing material includes V⁺⁴. The sealing material of thelight emitting device may be formed by irradiation of electro-magneticwaves in a wavelength range of 200 nm-10,000 nm.

According to another aspect of the present invention, there is provideda method of manufacturing a light emitting device, the method including:preparing a first substrate on which a light emitting unit is formed;preparing the composition for forming a sealing material describedabove; depositing the composition for forming a sealing material to anarea in which a sealing material is to be formed on a second substrate;heat treating the second substrate on which the composition for forminga sealing material is deposited, thereby forming heat-treatedcomposition for forming a sealing material; coupling the first substrateto the second substrate such that the heat-treated composition forforming a sealing material and the light emitting unit are interposedbetween the first substrate and the second substrate; and irradiatingelectro-magnetic waves on the heat-treated composition for forming asealing material to form a sealing material.

By using the glass fit, the composition for forming a sealing material,and the method of manufacturing a light emitting device, the sealingmaterial having good sealing property can be obtained, deterioration ofthe light emitting unit occurring when the sealing material is formedcan be prevented, and a light emitting device having a long lifetime canbe obtained at low costs.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages of the present inventionwill become more apparent by describing in detail exemplary embodimentsthereof with reference to the attached drawings in which:

FIG. 1 is a schematic sectional view of a light emitting deviceaccording to an embodiment of the present invention;

FIG. 2 is a schematic sectional view of one of a plurality of lightemitting units of the light emitting device of FIG. 1, according to anembodiment of the present invention;

FIGS. 3A through 3G are views illustrating a method of manufacturing alight emitting device according to an embodiment of the presentinvention;

FIG. 4 is a graph illustrating light transmission of a heat-treatedcomposition for forming a sealing material (heat treatment under N₂atmosphere) obtained according to Example 1 according to an embodimentof the present invention and a heat-treated composition for forming asealing material (heat treatment under an air atmosphere) obtainedaccording to Comparative Example 1;

FIG. 5 is an image illustrating a seal with of a sealing materialobtained according to Example 2, according to an embodiment of thepresent invention;

FIG. 6A is an image illustrating a lifetime property of an organic lightemitting device obtained according to Example 2, according to anembodiment of the present invention; and

FIG. 6B is an image illustrating a lifetime property of an organic lightemitting device obtained according to Comparative Example 2, accordingto an embodiment of the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS

Various embodiments of the present invention will now be described morefully with reference to the accompanying drawings.

A glass frit, which is an oxide including at least one kind of an ion,according to an embodiment of the present invention, includes V⁺⁴. TheV⁺⁴ of the glass fit absorbs electro-magnetic waves having variouswavelengths, so that the glass frit having the V⁺⁴ can be softened byirradiation of electro-magnetic waves. For example, the V⁺⁴ can absorblaser light having a wavelength of 810 nm.

The glass fit can further include other ions, in addition to the V⁺⁴.For example, the glass frit can include at least one ion selected fromthe group consisting of V⁺⁶, Ba⁺², Zn⁺², Te⁺⁴, Fe⁺³, Cu⁺², Nd⁺², K⁺¹,Sb⁺³, P⁺⁵, Ti⁺², Al⁺³, B⁺³, W⁺⁶, Sn⁺², Bi⁺³, Ca⁺², Si⁺⁴, Zr⁺⁴, and Mg⁺².However, the glass fit is not limited thereto.

In particular, the glass frit can further include V⁺⁶, Ba⁺², Zn⁺², andTe⁺⁴; or the glass fit can further include a Ba⁺², Zn⁺², and Te⁺⁴.

Some of the ions included in the glass fit can be induced from areductant that reduces V⁺⁶ included in the glass frit into V⁺⁴. Forexample, Al⁺³, Sn⁺², Mg⁺², Cu⁺², or a Zn⁺² can be induced from Al, Sn,Mg, Cu, or Zn, which are reductants that reduce V⁺⁶ included in theglass frit into V⁺⁴ and are added when the glass frit is manufactured.In addition, the reductant that reduces V⁺⁶ included in the glass fritinto V⁺⁴ can also be C (carbon). When the reductant is C, a small amountof organic materials can remain in the glass frit.

The glass frit may have an average particle size of 0.1 μm-30 μm, morespecifically, 0.5 μm-15 μm to effectively absorb electro-magnetic waves.The largest particle size of the glass fit may be in the range of 1μm-150 μm, more specifically, 3 μm-30 μm.

A method of manufacturing the glass frit having V⁺⁴ described above willnow be described in detail.

An oxide, such as V₂O₅, and a reductant that reduces V⁺⁵ into V⁺⁴ aremixed. The oxide can be V₂O₅, BaO, ZnO, TeO₂, Fe₂O₃, CuO, NdO, K₂O,Sb₂O₃, P₂O₅, TiO, Al₂O₃, B₂O₃, WO₆, SnO, Bi₂O₃, CaO, SiO₂, or ZrO₂, notlimited thereto. The reductant can be Al, Sn, Mg, Cu, Zn, or C, however,the reductant is not limited thereto.

Then, the mixture of the reductant and the oxide is heat treated in amelting pot. The heat treatment temperature may vary according to thekind and amount of oxide and reductant that are to be melted. Forexample, the heat treatment can be performed at approximately 600°C.-1200° C. for 10-240 minutes. The melted product is cooled to yieldglass and then the glass is ground to obtain a glass frit having V⁺⁴.The glass frit having V⁺⁴ may be included in a composition for forming asealing material of a light emitting device. The glass fit having V⁺⁴has been described.

The composition for forming a sealing material of a light emittingdevice includes the glass fit having V⁺⁴, and thus the composition canabsorb electro-magnetic waves in the wavelength range of 200 nm-10,000nm. Accordingly, the composition for forming a sealing material of alight emitting device can be effectively softened by irradiation ofelectro-magnetic waves in the wavelength range of 200 nm-10,000 nm.

When the composition for forming a sealing material is softened byirradiation of electro-magnetic waves, the volume of the composition forforming a sealing material of a light emitting device can be increasedand thus, a sealing material having good sealing properties may not beobtained. Accordingly, the composition for forming a sealing material ofa light emitting device may further include a filler that lowers athermal expansion coefficient.

The filler that lowers a thermal expansion coefficient can be azirconium-tungsten-phosphate based filler; a zirconium-phosphate basedfiller, such as zirconium phosphate; a zirconium-based filler, such aszirconium; an eucrytite-based filler, such as β-eucrytite; acordierite-based filler; alumina; silica; zinc silicate; aluminumtitanate; or a combination of at least two of these, however, the filleris not limited thereto.

More specifically, the zirconium-tungsten-phosphate based filler can be(Zr₂(WO₄)(PO₄)₂), however, the filler is not limited thereto.

The filler included in the composition for forming a sealing material ofa light emitting device may be softened by irradiation ofelectro-magnetic waves. In terms of the softening of the filler, theaverage particle diameter of the filler may be in the range of 0.1 μm-30μm, more specifically, 0.5 μm-15 μm. The largest particle diameter ofthe filler may be in the range of 1 μm-150 μm, more specifically, 3μm-30 μm.

The thermal expansion coefficient of the composition for forming asealing material of a light emitting device may be in the range of25×10⁻⁷/° C.-95×10⁻⁷/° C., more specifically, 35×10⁻⁷/° C.-65×10⁻⁷/° C.Therefore, a misalignment of substrates due to a change in volume of thecomposition resulting from irradiation of electro-magnetic waves whenthe sealing materials of the light emitting device are formed can beprevented.

The amount of filler may be determined in consideration of the thermalexpansion coefficient range and a sufficient amount of glass frit thatis required. For example, the amount of filler may be in the range of 5parts by weight-80 parts by weight, more specifically, 20 parts byweight-60 parts by weight, based on 100 parts by weight of the totalamount of glass frit and filler.

The composition for forming a sealing material of a light emittingdevice may further include a vehicle so as to obtain sufficientprinting, viscosity, and flowing properties. The vehicle can be anorganic material so that the vehicle can decompose when the compositionfor forming a sealing material of a light emitting device is loaded ontoa substrate and then heat treated.

For example, the vehicle may include a resin and a solvent. The resinmay include at least one resin selected from the group consisting of anacryl-based resin, a methacryl-based resin, a vinyl-based resin, anepoxy-based resin, a urethane-based resin, and a cellulose-based resin.However, the resin is not limited thereto. The solvent may include atleast one compound selected from the group consisting of terpinol,dihydro terpinol, butylcarbitolacetate, butyl carbitol, and2,2,4-trimethyl-1,3-pentadiol monobutyrate. However, the solvent is notlimited thereto.

More specifically, the acryl-based resin of the vehicle can bebutylacrylate or ethylhexylacrylate; the methacryl-based resin of thevehicle can be propyleneglycolmethacrylate or tetrahydrofurfurylmethacrylate; the vinyl-based resin of the vehicle can be vinylacetate,N-vinylpyrrolidone; the epoxy-based resin of the vehicle can becycloaliphatic epoxide or epoxy acrylate; the urethane-based resin ofthe vehicle can be urethane acrylate; and the cellulose-based resin ofthe vehicle can be ethylcellulose or cellulosenitrate. However, theseresins of the vehicle are not limited thereto.

The amount of vehicle of the composition may be determined inconsideration of printing, viscosity, and flowing properties of thecomposition for forming a sealing material of a light emitting device.For example, the amount of vehicle of the composition may be in therange of 10 parts by weight-60 parts by weight, more specifically, 20parts by weight-50 parts by weight based on 100 parts by weight of thecomposition for forming a sealing material of a light emitting device.

Another composition for forming a sealing material of a light emittingdevice according to another embodiment of the present invention includesa glass frit having V⁺⁵ and a filler. In this case, the filler of thecomposition can be a zirconium-tungsten-phosphate based filler.

In the current embodiment, the term, “the glass frit having V⁺⁵” means aglass frit which does not include V⁺⁴. The sealing material of the lightemitting device necessarily include V⁺⁴, however, the sealing materialcan include the V⁺⁴ obtained according to various methods. For example,as described above, the glass frit itself may include the V⁺⁴.Alternatively, even when a glass fit does not include V⁺⁴, V⁺⁵ can bereduced into the V⁺⁴ by using a reductant or by performing a heattreatment in a reducing atmosphere. In detail, even when the compositionfor forming a sealing material of a light emitting device including theglass frit having the V⁺⁵ and the filler includes a glass frit that doesnot include V⁺⁴, the V⁺⁴ can be obtained by using a reductant or byperforming a heat treatment in a reducing atmosphere.

The glass frit having V⁺⁵ of the composition for forming a sealingmaterial of a light emitting device may further include at least one ionselected from the group consisting of a Ba⁺², Zn⁺², Te⁺⁴, Fe⁺³, Cu⁺²,Nd⁺², K⁺¹, Sb⁺³, P⁺⁵, Ti⁺², Al⁺³, B⁺³, W⁺⁶, Sn⁺², and Bi⁺³, Ca⁺², Si⁺⁴,Zr⁺⁴, and Mg⁺². However, the glass frit having V⁺⁵ is not limitedthereto.

More specifically, the glass frit having V⁺⁵ may include a Ba⁺², Zn⁺²,and Te⁺⁴.

The glass frit having V⁺⁵ may have an average particle diameter of 0.1μm-30 μm, more specifically, 0.5 μm-15 μm so as to effectively absorbelectro-magnetic waves. The largest particle diameter of the glass frithaving V⁺⁵ may be in the range of 1-150 μm, more specifically, 3 μm-30μm.

The zirconium-tungsten-phosphate based filler included in thecomposition for forming a sealing material can be (Zr₂(WO₄)(PO₄)₂),however, the zirconium-tungsten-phosphate based filler is not limitedthereto.

The composition for forming a sealing material of a light emittingdevice may further include a filler selected from a zirconium-phosphatebased filler, such as, zirconium phosphate; a zirconium-based filler,such as zirconium; an eucrytite-based filler, such as β-eucrytite; acordierite-based filler; alumina; silica; zinc silicate; and aluminumtitanate, however, the filler is not limited thereto.

The filler included in the composition for forming a sealing material ofa light emitting device may be softened by irradiation ofelectro-magnetic waves. In terms of the softening of the filler, theaverage particle diameter of the filler may be in the range of 0.1 μm-30μm, more specifically, 0.5 μm-30 μm. The largest particle diameter ofthe filler may be in the range of 1-150 μm, more specifically, 3 μm-30μm.

A thermal expansion coefficient of the composition for forming a sealingmaterial of a light emitting device may be in the range of 25×10⁻⁷/°C.-95×10⁻⁷/° C., more specifically, 35×10⁻⁷/° C.-65×10⁻⁷/° C. Therefore,a misalignment of substrates due to a change in volume of thecomposition resulting from irradiation of electro-magnetic waves whenthe sealing material of the light emitting device is manufactured can beprevented.

The amount of filler may be determined in consideration of the thermalexpansion coefficient range and a sufficient amount of glass frit thatis required. For example, the amount of filler may be in the range of 5parts by weight-80 parts by weight, more specifically, 20 parts byweight-60 parts by weight, based on 100 parts by weight of the totalamount of glass frit and filler.

The composition for forming a sealing material of a light emittingdevice including a glass fit having V⁺⁵ and a filler may further includea reductant. The reductant reduces the V⁺⁵ into V⁺⁴. The composition forforming a sealing material of a light emitting device is coated on asubstrate, heat treated, and then subjected to irradiation ofelectro-magnetic waves. When the composition is heat treated, the V⁺⁵ ofthe glass frit can be reduced into V⁺⁴ by the reductant included in thecomposition for forming a sealing material.

The reductant of the composition can be Al, Sn, Mg, Cu, Zn, or C,however, the reductant of the composition is not limited thereto. Theamount of reductant may vary according to the amount of glass frit, andthe heat treatment temperature of the composition and heat treatmenttime of the composition for forming a sealing material of a lightemitting device may vary, and the amount of reductant of the compositioncan be in the range of approximately 0.01 parts by weight-20 parts byweight, more specifically, 0.1 parts by weight-2 parts by weight, basedon 100 parts by weight of the glass frit.

The composition for forming a sealing material of a light emittingdevice may further include a vehicle so as to obtain sufficientprinting, viscosity, and flowing properties. The vehicle of thecomposition can be an organic material so that the vehicle of thecomposition can decompose when the composition for forming a sealingmaterial of a light emitting device is loaded onto a substrate and thenheat treated.

For example, the vehicle of the composition may include a resin and asolvent. The resin of the vehicle may include at least one resinselected from the group consisting of an acryl-based resin, amethacryl-based resin, a vinyl-based resin, an epoxy-based resin, aurethane-based resin, and a cellulose-based resin. However, the resin ofthe vehicle is not limited thereto. The solvent of the vehicle mayinclude at least one compound selected from the group consisting ofterpinol, dihydro terpinol, butylcarbitolacetate, butyl carbitol, and2,2,4-trimethyl-1,3-pentadiol monobutyrate. However, the solvent of thevehicle is not limited thereto.

Some of the vehicles described above can act as a reductant that reducesV⁺⁵ into V⁺⁴.

More specifically, the acryl-based resin can be butylacrylate orethylhexylacrylate; the methacryl-based resin can bepropyleneglycolmethacrylate or tetrahydrofurfuryl methacrylate; thevinyl-based resin can be vinylacetate, N-vinylpyrrolidone; theepoxy-based resin can be cycloaliphatic epoxide or epoxy acrylate; theurethane-based resin can be urethane acrylate; and the cellulose-basedresin can be ethylcellulose or cellulosenitrate. However, these resinsare not limited thereto.

The amount of vehicle may be determined in consideration of printing,viscosity, and flowing properties of the composition for forming asealing material of a light emitting device. For example, the amount ofvehicle may be in the range of 10 parts by weight-60 parts by weight,more specifically, 20 parts by weight-50 parts by weight, based on 100parts by weight of the composition for forming a sealing material of alight emitting device.

As described above, the composition for forming a sealing materialincluding a glass frit having V⁺⁴, and the composition for forming asealing material including a glass fit having V⁺⁵ ion can be used toform a sealing material that encapsulate an electronic device, such asan organic light emitting device, an electron emission device, or aplasma display panel, so as to prevent permeation of oxygen and/or watertherein.

However, the glass fit having V⁺⁴ ion of the composition for forming asealing material including a glass frit having V⁺⁴ ion can furtherinclude V⁺⁵ ion in addition to the V⁺⁴ ion. Accordingly, as required,the composition for forming a sealing material including a glass fithaving V⁺⁴ ion can further include a reductant which can be added to thecomposition for forming sealing materials including a glass fit havingV⁺⁵, so that residual V⁺⁵ can be additionally reduced.

A light emitting device according present invention include a firstsubstrate; a second substrate; a light emitting unit interposed betweenthe first substrate and the second substrate; and a sealing materialbonding the first substrate to the second substrate and sealing thelight emitting unit, wherein the sealing material includes V.

FIG. 1 is a schematic sectional view of a light emitting device 10including a plurality of light emitting units 13 such as organic lightemitting units, according to an embodiment of the present invention.

Referring to FIG. 1, the light emitting device 10 includes a firstsubstrate 11, a second substrate 15, and the light emitting units 13formed on the first substrate 11. In the light emitting device 10 ofFIG. 1, the second substrate 15 acts as an encapsulation substrate. Eachof a plurality of sealing materials 18 bonding the first substrate 11 tothe second substrate 15 and sealing each of the light emitting units 13,are interposed between the first substrate 11 and the second substrate15. Each of the sealing materials 18 includes V⁺⁴.

The first substrate 11 can be any substrate that is commercially used inlight emitting devices. For example, the first substrate 11 can be aglass substrate, a metallic substrate, a plastic substrate, or the like,however, the first substrate 11 is not limited thereto.

The light emitting units 13 are formed on the first substrate 11.

FIG. 2 is a schematic sectional view of one of the light emitting units13 of the light emitting device 10 of FIG. 1, according to an embodimentof the present invention. More specifically, the light emitting units 13are of an active matrix (AM) type.

Referring to FIG. 2, a buffer layer 41 is formed on the substrate 11 inorder to flatten the substrate 11 and to prevent permeation of impureatoms. The buffer layer 41 can be formed of at least one of SiO₂ andSiNx, however, the buffer layer 41 can be formed of other materials.

A thin film transistor (TFT) is formed on the substrate 11 and can becomprised in each pixel of the light emitting device 10.

More specifically, a semiconductor layer 42 having a predeterminedpattern is formed on the buffer layer 41. The semiconductor layer 42 maybe formed of an inorganic semiconducting material, such as an amorphoussilicon or a poly silicon, or an organic semiconducting material, suchas pentacene, and may include a source region, a drain region, and achannel region.

A gate insulating layer 43 formed of SiO₂ or SiNx is formed on thesemiconductor layer 42, and a gate electrode 44 is formed on the gateinsulating layer 43. The gate electrode 44 may be formed of MoW orAl/Cu, however, the gate electrode 44 can be formed of other materials.The material of the gate electrode 44 can be determined in considerationof an adherence of the gate electrode 44 with an adjacent layer,flatness of a layer that is to-be-deposited on the gate electrode 44,electrical resistance of the gate electrode 44, and processability ofthe gate electrode 44. The gate electrode 44 is connected to a gate linethat applies a TFT on/off signal (not shown).

An interlayer insulating layer 45 is formed on the gate electrode 44,and a source electrode 46 and a drain electrode 47 are formed on theinterlayer insulating layer 45. The source electrode 46 and the drainelectrode 47 can be formed of Au; Pd; Pt; Ni; Rh; Ru; Ir; Os; Al; Mo; analloy formed of at least two kinds of metals, such as an Al:Nd alloy ora MoW alloy; or a metal oxide, such as ITO, IZO, NiO, Ag₂O, In₂O₃—Ag₂O,CuAlO₂, SrCu₂O₂, or Zr-coated ZnO, however, the source electrode 46 andthe drain electrode 47 are not limited thereto. In addition, the sourceelectrode 46 and the drain electrode 47 can be formed of a combinationof at least two selected from the metals and metal oxides describedabove.

The source electrode 46 and the drain electrode 47 are electricallyconnected to the source and drain regions of the semiconductor layer 42through a contact hole, respectively. A passivation layer 48 is formedon the TFT described above.

The passivation layer 48 may include at least one of an inorganic and anorganic material. The inorganic material can be SiO₂, SiNx, SiON, Al₂O₃,TiO₂, Ta₂O₅, HfO₂, ZrO₂, BST, or PZT. The organic material can be apolymer, such as PMMA or PS; a polymer derivative including a phenolgroup; an acryl-based polymer; an imide-based polymer; anarylether-based polymer; an amide-based polymer; a fluoride-containingpolymer; a p-xylene-based polymer; a vinylalcohole-based polymer; or ablend of these, however, the organic material is not limited thereto.The passivation layer 48 may have a composite stack structure consistingof an inorganic insulating layer and an organic insulating layer.

A first electrode 51 acting as an anode of an organic light emittingunit 50 is formed on the passivation layer 48. The first electrode 51 ofthe organic light emitting unit 50 can be a transparent electrode formedof, for example, a material having a high work function, such as ITO,IZO, ZnO, or In₂O₃. Alternatively, the first electrode 51 of the organiclight emitting unit 50 can be a reflective electrode formed by forming areflective layer formed of Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li,Ca, or a combination of these, and then depositing ITO, IZO, ZnO, orIn₂O₃, each of which has a high work function, on the reflective layerof the reflective electrode. The first electrode 51 of the organic lightemitting unit 50 is electrically connected to the drain electrode 47 ofthe TFT described above.

A pixel define layer 49 is formed on the first electrode 51. The pixeldefine layer 49 exposes a part of the first electrode 51 and has anopening defining where an organic layer 52 of the organic light emittingunit 50 is formed. The organic layer 52 of the organic light emittingunit 50 is formed in the opening defined by the pixel define layer 49and a second electrode 53 acting as a cathode of the organic lightemitting unit 50 is formed on the organic layer 52.

The organic layer 52 that is interposed between the first electrode 51and the second electrode 53 emits light by an electrical operation ofthe first electrode 51 and the second electrode 53. The organic layer 52may be formed with a low molecular weight or high molecular weightorganic material. The organic layer 52 may include at least one layerselected from the group consisting of a hole injection layer, a holetransport layer, an electron blocking layer, an emission layer, a holeblocking layer, an electron transport layer, and an electron injectionlayer, as required. The low molecular weight organic material of theorganic layer 52 can be copper phthalocyanine (CuPc), N,N′-Dinaphthalene-1-yl-N,N′-diphenyl-benzidine (NPB), tris-8-hydroxyquinolinealuminum (Alq3), or the like, however, the low molecular weight organicmaterial of the organic layer 52 is not limited thereto. The highmolecular weight organic material of the organic layer 52 can bepoly-2,4-ethylene-dihydroxy thiophene (PEDOT), polyaniline (PANI), orthe like, however, the high molecular weight organic material of theorganic layer 52 is not limited thereto. The organic layer 52 can beformed by various other methods, such as deposition, LITI (Laser InducedThermal Imaging), inkjet printing, or spin coating.

The second electrode 53 can be a transparent electrode or reflectiveelectrode formed of a material having a low work function, such as Ag,Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, or Ca. In addition, an assistantelectrode or bus electrode line can be further in addition to thetransparent electrode or the reflective electrode using a transparentconductive material, such as ITO, IZO, ZnO, or In₂O₃.

A protective layer (not shown) can be further formed on the secondelectrode 53 to provide resistance to heat, and chemical materials, andthe permeation of water, so that the permeation of water and/or oxygeninto the organic layer 52 can be additionally prevented. The protectivelayer may have various other structures. For example, the protectivelayer may include an inorganic layer or include an alternative structureof an inorganic layer and an organic layer.

The inorganic layer of the protective layer may include at least oneoxide selected from the group consisting of silicon nitride, aluminumnitride, zirconium nitride, titanium nitride, hafnium nitride, tantalumnitride, silicon oxide, aluminum oxide, titanium oxide, tin oxide,cerium oxide, and silicon oxide nitride (SiON). However, the inorganiclayer can be formed of other materials.

The organic layer of the protective layer can be formed of across-linked product of a benzocyclobutene ring-containing compound orhydrosilsesquioxane, however, the organic layer of the protective layercan be formed of other materials.

The inorganic layer and organic layer of the protective layer aredescribed in detail in Korean Patent Laid-open Publication No.2005-0077919, which is referred and incorporated in the currentspecification.

One of the light emitting units 13 of the light emitting device 10according to an embodiment of the present invention has been describedwith reference to FIG. 2, however, the light emitting units 13 of thelight emitting device 10 can have various other structures.

In the light emitting device 10 of FIG. 1, the second substrate 15 canbe an encapsulation substrate such as a glass substrate or a transparentplastic substrate. When the second substrate 15 is a plastic substrate,a protective film can be formed on an inner surface of the plasticsubstrate in order to prevent the permeation of water. The protectivefilm of the transparent plastic substrate has a resistance to heat, andchemical materials, and prevents the permeation of water. When theencapsulation substrate of the second substrate 15 is formed of atransparent material, such a structure is suitable for a front emissiontype light emitting device.

The sealing materials 18 bond the first substrate 11 to the secondsubstrate 15 and seal the light emitting units 13, in particular, toprevent the permeation of oxygen and water into the light emitting units13 by being interposed between the first substrate 11 and the secondsubstrate 15.

Each of the sealing materials 18 includes V⁺⁴. The V⁺⁴ of each of thesealing materials 18 can effectively absorb electro-magnetic waves inthe wavelength range of 200 nm-10,000 nm, such as ultraviolet rays,visible rays, or infrared rays. In terms of the absorption ofelectro-magnetic waves, the amount of V⁺⁴ included in each of thesealing materials 18 may be in the range of 0.001 mol %-50 mol %, morespecifically, 0.01 mol %-30 mol %. The sealing materials 18 can beformed using a laser or a light-emitting lamp. The laser or thelight-emitting lamp that is used to form the sealing materials 18 canselectively irradiate electro-magnetic waves to an area in which thesealing materials 18 are each formed, so that the light emitting units13 of the light emitting device 10 do not substantially deteriorate whenthe sealing materials 18 are formed.

Each of the sealing materials 18 may further include a filler.

The filler of each of the sealing materials 18 lowers the thermalexpansion coefficient of the composition for forming the sealingmaterials.

The filler of each of the sealing materials 18 can be azirconium-tungsten-phosphate based filler; a zirconium-phosphate basedfiller, such as zirconium phosphate; a zirconium-based filler, such aszirconium; an eucrytite-based filler, such as β-eucrytite; acordierite-based filler; alumina; silica; zinc silicate; aluminumtitanate; or a combination of at least two of these, however, the fillerof each of the sealing materials 18 is not limited thereto.

More specifically, the zirconium-tungsten-phosphate based filler can be(Zr₂(WO₄)(PO₄)₂), however, the zirconium-tungsten-phosphate based filleris not limited thereto.

The filler of each of the sealing materials 18 may be softened byirradiation of electro-magnetic waves. In terms of the softening of thefiller, the average particle diameter of the filler is in the range of0.1 μm-30 μm, more specifically, 0.5 μm-15 μm. The largest particle sizeof the filler may be in the range of 1 μm-150 μm, more specifically, 3μm-30 μm.

The amount of filler may be determined in consideration of a thermalexpansion coefficient range and a sufficient amount of the glass fritthat is required. For example, the amount of filler may be in the rangeof 5 parts by weight-80 parts by weight, more specifically, 20 parts byweight-60 parts by weight, based on 100 parts by weight of the totalamount of glass frit and filler.

Each of the sealing materials 18 may further include, in addition to theV⁺⁴, various other ions. For example, each of the sealing materials 18may further include at least one ion selected from the group consistingof V⁺⁵, Ba⁺², Zn⁺², Te⁺⁴, Fe⁺³, Cu⁺², Nd⁺², K⁺¹, Sb⁺³, P⁺⁵, Ti⁺², Al⁺³,B⁺³, W⁺⁶, Sn⁺², Bi⁺³, Ca⁺², Si⁺⁴, Zr⁺⁴, and Mg⁺². However, each of thesealing materials 18 is not limited thereto.

More specifically, each of the sealing materials 18 may further includeV⁺⁵, Ba⁺², Zn⁺², and Te⁺⁴, or include a Ba⁺², Zn⁺², and Te⁺⁴.

Some of the ions included in each of the sealing materials 18 can beinduced from a reductant that reduces V⁺⁶ included in the glass fritinto V⁺⁴. For example, Al⁺³, Sn⁺², Mg⁺², Cu⁺², and Zn⁺² can be inducedfrom Al, Sn, Mg, Cu, and Zn, each of which is a reductant that reducesV⁺⁵ included in the glass frit into V⁺⁴, and is added when a glass fritis manufactured. Meanwhile, each of the sealing materials 18 can includea small amount of an organic material induced from C (carbon) that isused as a reductant that reduces V⁺⁶ into V⁺⁴.

A method of manufacturing the light emitting device 10 described aboveaccording to an embodiment of the present invention will now bedescribed in detail with reference to FIGS. 3A through 3G.

Referring to FIG. 3A, a first substrate 21 on which a plurality of lightemitting units 23 are formed is prepared. The first substrate 21 can beany substrate that is used in various electronic devices, as describedabove, and the light emitting units 23 can be organic light emittingunits, however, the light emitting units 23 are not limited thereto. Thelight emitting units 23 can be manufactured using a commercially knownmethod.

Referring to FIGS. 3B and 3C, a composition for forming a sealingmaterial 27 is provided to areas where the sealing materials (seereference number 28 in FIG. 3G) are to be formed on a second substrate25. The composition for forming a sealing material 27 are provided torespectively surround the organic light emitting units 23 after thefirst substrate 21 is coupled to the second substrate 25. However, theareas where the sealing materials are to be formed on the secondsubstrate are not limited to the areas shown in FIGS. 3B and 3C. FIG. 3Bis cross-sectional view of FIG. 3C. The second substrate 25 can beencapsulation substrate and can be formed from glass or plasticmaterials.

The composition for forming a sealing material 27 can be the compositionfor forming a sealing material including a glass fit having V⁺⁴ or thecomposition for forming a sealing material including a glass frit havingV⁺⁵ and a filler as described above.

The composition for forming a sealing material 27 can be provided on thesecond substrate 25 using various known methods, such as an inkjetprinting method or a screen printing method.

The composition for forming a sealing material 27 may or may not includeV⁺⁴. For example, when the composition for forming a sealing material 27includes a glass frit having V⁺⁴, the composition for forming a sealingmaterial 27 includes the V. However, when the composition for forming asealing material 27 does not include a glass frit having V⁺⁴, thecomposition for forming a sealing material 27 may not include the V⁺⁴.In the latter case, the V⁺⁴ can be generated by a heat treatment asdescribed later.

Subsequently, the second substrate 25 to which the composition forforming a sealing material 27 is provided is heat treated therebyforming heat-treated composition for a sealing material 27′ asillustrated in FIG. 3D.

Due to the heat treatment of the composition for forming a sealingmaterial 27, the composition for forming a sealing material 27 can beformed in a film having a predetermined shape, and some of the V⁺⁵ inthe composition for forming a seal sealing material 27 can be reduced tothe V⁺⁴. In the specification, the term “heat-treated composition forforming a sealing material” is used to represent above changes after theheat treatment of the composition for forming a sealing material 27.Accordingly, as illustrated in FIG. 3E, the coupling of the firstsubstrate 21 to the second substrate 25 can be effectively performed.Further, as illustrated in FIG. 3F, when electro-magnetic waves isirradiated as illustrate in FIG. 3F, the electro-magnetic waves can beeffectively absorbed by V⁺⁴. As a result of the heat treatment, avehicle in the composition for forming a sealing material 27 candecompose.

The heat treatment can be performed in a reducing atmosphere or an airatmosphere. The reducing atmosphere can be an N₂ atmosphere or ahydrogen atmosphere. Due the heat treatment, V⁺⁵ in the composition forforming sealing material 27 can be reduced into V⁺⁴. In particular, whenthe glass frit does not include V⁺⁴ and the composition for forming asealing material 27 does not include a reductant that reduces V⁺⁵ intoV⁺⁴, it is desired to perform the heat treatment in the reducingatmosphere.

When the composition for forming a sealing material 27 includes thereductant, the heat treatment atmosphere is not always the reducingatmosphere. When the composition for forming the sealing materials 27includes a reductant, such as Al, Sn, Mg, Cu, Zn, or C, the reductant isoxidized and reduces V⁺⁵ into V⁺⁴ when the heat treatment is performed.

The heat treatment temperature and heat treatment time may be determinedin consideration of a temperature and time at which V⁺⁵ can be reducedinto V⁺⁴ and a temperature and time at which the vehicle in thecomposition for forming a sealing material can decompose. For example,the heat treatment temperature and heat treatment time may be in therange of 250° C.-750° C., more specifically, 350° C.-550° C., and 5-240minutes, more specifically, 10-120 minutes, respectively.

Each of the heat-treated composition for forming a sealing material 27′as illustrated in FIG. 3D necessarily includes V⁺⁴. The V⁺⁴ can be V⁺⁴included in the glass frit itself, V⁺⁴ generated by reducing V⁺⁵ in theglass frit with a reductant in the composition for forming sealingmaterials during the heat treatment, or V⁺⁴ generated as a result of theheat treatment in a reducing atmosphere of V⁺⁵ of the glass frit.

Then, as illustrated in FIG. 3E, the first substrate 21 is coupled withthe second substrate 25 so that the heat-treated composition for forminga sealing material 27′ and the light emitting units 23 are interposedbetween the first substrate 21 and the second substrate 25. At thispoint, for example, each of the heat-treated composition for forming asealing material 27′ may surround each of the light emitting units 23.

Then, as illustrated in FIG. 3F, electro-magnetic waves 29 areirradiated on the heat-treated composition for forming a sealingmaterial 27′ to form a plurality of sealing materials 28 as illustratedin FIG. 3G, which bond the first substrate 21 to the second substrate 25and respectively seal the light emitting units 23.

The electro-magnetic waves 29 can be irradiated on the heat-treatedcomposition for forming a sealing material 27′ through the firstsubstrate 21 or the second substrate 25. At this point, the V⁺⁴ in theheat-treated composition for forming a sealing material 27′ absorbs theelectro-magnetic waves 29, so that the composition is softened and/ormelted by the resulting energy and thus the sealing materials 28 areformed.

The electro-magnetic waves 29 may have a wavelength of 200 nm-10,000 nmso that the V⁺⁴ can absorb the electro-magnetic waves 29. Accordingly,the electro-magnetic waves 29 can be ultraviolet rays, visible rays, orinfrared rays. The electro-magnetic waves 29 can be provided using alaser or light-emitting lamp emitting electro-magnetic waves in such awavelength range. However, electro-magnetic waves 29 can be providedusing other devices. For example, the electro-magnetic waves 29 can be alaser ray with a wavelength of 810 nm. The glass fit may have a lighttransmittance of about 40% or less for light with a wavelength fromabout 650 nm to about 1000 nm

As illustrated in FIG. 3F, according to the current embodiment, theelectro-magnetic waves 29 can be selectively irradiated only on theareas where the sealing materials 28 are to be formed. As a result,deterioration of the light emitting units 23 occurring when the sealingmaterials 28 are formed can be prevented.

The method of manufacturing a light emitting device according to anembodiment of the present invention has been described with reference toFIGS. 3A through 3G. However, the method is not limited thereto.

A plurality of sealing materials of a light emitting device according toan embodiment of the present invention can be formed by irradiation ofelectro-magnetic waves. As such, the heat-treated composition forforming a sealing material 27′ necessarily includes V⁺⁴. The V⁺⁴included in the heat-treated composition for forming a sealing material27′ can be obtained using various methods as described below:

a) a composition for forming a sealing material including a glass frithaving V⁺⁴ can be used;

b) A heat treatment where V⁺⁵ can be reduced into V⁺⁴ by a reductantthat reduces V⁺⁵ into V⁺⁴ in a composition for forming a sealingmaterial; and

c) V⁺⁵ in a composition for forming a sealing material can be reducedinto V⁺⁴ by performing a heat treatment in a reducing atmosphere.

At least one of a), b), and c) can be used. For example, the compositionfor forming a sealing material including a glass frit having V⁺⁴ isfurther subjected to a heat treatment in a reducing atmosphere, so thatV⁺⁵ in the glass frit can be additionally reduced into V⁺⁴.

The present invention will be described in further detail with referenceto the following examples. These examples are for illustrative purposesonly and are not intended to limit the scope of the present invention.

Example 1 A. Preparing of Glass Frit/Composition

29.2 g of V₂O₅, 5.2 g of ZnO, 14.7 g of BaO, and 50.8 g of TeO₂ aremixed in a Pt melting pot, and then heat treated at 800° C. forapproximately one hour in an electric oven. The melted product that isobtained as a result of the heat treatment is cooled and ball milled,thereby obtaining a glass fit having an average particle diameter of 2μm and a largest particle diameter of 10 μm. The glass frit includesV⁺⁵, Zn⁺², Ba⁺², and Te⁺⁴.

50 g of the glass fit is mixed with 50 g of Zr₂(WO₄)(PO₄)₂ having anaverage particle diameter of 3 μm and a largest particle diameter of 15μm (product name: ZWP, manufacturer: KCM Co.), and then a thermalexpansion coefficient of the mixture of the glass fit and theZr₂(WO₄)(PO₄)₂ is measured using a thermal mechanical analysis (TMA)apparatus. As a result, the thermal expansion coefficient of the mixtureof the glass frit and the Zr₂(WO₄)(PO₄)₂ is approximately 50×10⁻⁷/° C.

50 g of a vehicle including an ethylcellulose-based resin is added tothe mixture of the glass frit and the Zr₂(WO₄)(PO₄)₂ and stirred,thereby obtaining a composition for forming a sealing material.

B. Heat Treatment of a Composition

The composition for forming a sealing material obtained from themanufacturing process described above in step A of Example 1 is coatedon a glass substrate by a screen printing method to a width of 600 μmand thickness of 30 μm, and then the coated result is heat treated at420° C. for 4 hours in an N₂ atmosphere.

Comparative Example 1

A composition for forming sealing materials is manufactured using thesame method described in step A of Example 1. Then, the composition forforming a sealing material is heat treated in the same manner as in stepB of Example 1, except that an air atmosphere is used instead of the N₂atmosphere.

Measurement Example 1 Light Transmission

A light transmission of the heat-treated composition for forming asealing material (heat treatment in an N₂ atmosphere) obtained accordingto Example 1 and the heat-treated composition for forming a sealingmaterial (heat treatment in an air atmosphere) obtained according toComparative Example 1 is measured by irradiating light with a wavelengthof 400 nm to 1100 nm through each of the glass substrates, and then arespective light transmission is measured using an UV-VIS Spectrometer.The results are shown in FIG. 4. Referring to FIG. 4, at a wavelength of810 nm, the light transmission of the heat-treated composition for aforming sealing material (heat treatment in an N₂ atmosphere) obtainedaccording to Example 1 is 17.5%, and the light transmission of theheat-treated composition for forming a sealing material (heat treatmentin an air atmosphere) obtained according to Comparative Example 1 is60.5%. That is, it is found that the heat-treated composition forforming a sealing material (heat treatment in an N₂ atmosphere) obtainedaccording to Example 1 effectively can absorb visible-infrared lightresulting from a reduction of a V⁺⁵ into V⁺⁴ as a result of the heattreatment in an N₂ atmosphere.

Example 2

A first glass substrate including an organic light emitting unit that ismanufactured by SDI Co., Ltd. is prepared. A composition forming asealing material is prepared in the same manner as in step A of Example1, and then provided on a second glass substrate that functions as anencapsulation substrate in the same manner as in step B of Example 1.The second glass substrate on which the composition for forming asealing material is provided is heat treated at 420° C. for 4 hours inan N₂ atmosphere to form a heat-treated composition for forming asealing material.

Then, the first glass substrate is coupled to the second glass substratesuch that the heat-treated composition for forming a sealing materialrespectively surround the organic light emitting units, and then a laserwith a wavelength of 810 nm is irradiated on the heat-treatedcomposition for forming a sealing material to form sealing materials.

FIG. 5 is an image of a seal width of one of the sealing materialobtained from Example 2. Referring to FIG. 5, the seal width of thesealing material is approximately 500 μm. As a result, it is found thatthe heat-treated composition for forming a sealing material absorbed thelaser and thus melted, so that the sealing materials are formed.

Comparative Example 2

This experiment is performed in the same manner as in Example 2, exceptthat the composition for forming a sealing material is heat treated inan air atmosphere instead of the N₂ atmosphere. As a result, it isimpossible to achieve a formation of the sealing material by irradiationof a laser with a wavelength of 810 nm on the sealing materials, so thatthe first glass substrate and the second glass substrate are not sealed.Such a result may result from the assumption that V⁺⁴ is notsufficiently formed by heat treatment in an air atmosphere and thus thelaser is not effectively absorbed.

Comparative Example 3

An organic light emitting device is manufactured in the same manner asin Example 2, except that an epoxy resin, which is an organic sealingmaterial, is coated on the second substrate instead of the compositionfor forming a sealing material, and then hardened to form a sealingmaterials.

Measurement Example 2 Lifetime Characteristics

The lifetimes of the organic light emitting devices obtained accordingto Example 2 and Comparative Example 3 are measured and shown in FIG. 6Aand FIG. 6B, respectively. More specifically, the organic light emittingdevices were left to sit in a relative humidity of 85% at 85° C. for 300hours, and the operation test of the organic light emitting devices isperformed to measure the lifetimes of the organic light emittingdevices. FIG. 6A is an image of the organic light emitting deviceobtained according to Example 2, and FIG. 6B is an image of the organiclight emitting device obtained according to Comparative Example 3. Bycomparing FIGS. 6A and 6B, dark spots were not substantially formed inthe image of FIG. 6A. Such a result may result from an assumption thatdeterioration due to water did not occur due to the sealing materials ofthe organic light emitting device obtained according to Example 2.Accordingly, it is found that a light emitting device according to anembodiment of the present invention has a long lifetime.

According to embodiments of the present invention, sealing materials canbe formed absorbing electro-magnetic waves which can be selectivelyprovided, such as a laser or light-emitting lamp. Therefore, adeterioration of a light emitting unit occurring when the sealingmaterials are formed can be prevented. Further, the sealing materialaccording to embodiments of the present invention has good sealingproperties. Thus, a light emitting device having a long lifetime can beobtained.

While the present invention has been particularly shown and describedwith reference to exemplary embodiments thereof, it will be understoodby one of ordinary skill in the art that various changes in form anddetails may be made therein without departing from the spirit and scopeof the present invention as defined by the following claims.

What is claimed is:
 1. A glass frit device comprising: a glass platecomprising a surface; and a glass frit comprising vanadium in the formof V⁺⁴, wherein the glass frit forms a closed loop on the surface of theglass plate, wherein the glass frit has a light transmittance of about50% or less for light with a wavelength of 810 nm; wherein the glass fitis in the form of a sintered body, and wherein the V⁺⁴ is present moreon the surface of the sintered body than the interior of the sinteredbody.
 2. The glass fit device of claim 1, wherein the sintered body haslight transmittance of 40% or less for light with the wavelength of 810nm.
 3. The glass fit device of claim 1, wherein the sintered body haslight transmittance of 40% or less for light with a wavelength fromabout 650 nm to about 1000 nm.
 4. The glass frit device of claim 1,wherein the V⁺⁴ is present in the glass frit in an amount from about0.0001 wt % to about 10 wt %.
 5. The glass frit device of claim 1,wherein the glass frit further comprises at least one ion selected fromthe group consisting of V⁺⁵, Ba⁺², Zn⁺², Te⁺⁴, Fe⁺³, Cu⁺², Nd⁺², K⁺¹,Sb⁺³, P⁺⁵, Ti⁺², Al⁺³, B⁺³, W⁺⁶, Sn⁺², Bi⁺³, Ca⁺², Si⁺⁴, Zr⁺⁴, and Mg⁺².6. The glass frit device of claim 1, wherein the glass frit furthercomprises at least one ion selected from the group consisting of V⁺⁵,Ba⁺², Zn⁺² and Te⁺⁴.
 7. The glass frit device of claim 1, wherein theglass frit further comprises at least one reductant selected from thegroup consisting of Sn, Al, Mg, Cu, and Zn.
 8. The glass frit device ofclaim 1, wherein the presence of the V⁺⁴ in the glass frit is detectableby X-ray Photoelectron Spectroscopy (XPS).
 9. A method of manufacturingthe glass fit device of claim 1, comprising: providing the glass platecomprising the surface; forming a closed loop structure of a pastecomposition; heating the closed loop structure so as to form the glassfrit forming a closed loop on the surface; and wherein the glass fritcomprises V⁺⁴ and has a light transmittance of about 50% or less forlight with a wavelength of 810 nm.
 10. The method of claim 9, whereinheating of the closed loop structure is performed under an N₂atmosphere.
 11. The method of claim 9, wherein the heat treatmenttemperature of the heating of the closed loop structure is from about250° C. to 750° C.
 12. The method of claim 9, wherein the heat treatmenttemperature of the heating of the closed loop structure is from about350° C. to 550° C.
 13. The method of claim 9, wherein the heat treatmenttemperature of the heating of the closed loop structure is 420° C. 14.The method of claim 9, wherein the heat treatment time of the heatingthe closed loop structure is from about 5 minutes to about 240 minutes.15. The method of claim 9, wherein the heat treatment time of theheating the closed loop structure is 240 minutes.
 16. A method of makinga display device, the method comprising: providing the glass frit deviceof claim 1; providing an intermediate device comprising a substrate andan array of light emitting devices formed on the substrate; arrangingthe glass frit device and the intermediate device such that the glassfrit is interposed between the glass plate and the substrate, andwherein the glass frit contacts the substrate while surrounding thearray; and applying a laser onto the glass frit so as to bond the glassfrit to the substrate.
 17. The method of claim 16, wherein the glassfrit has a light transmittance of the laser about 40% or less.
 18. Adisplay device comprising: a first substrate; a second substrate; anarray of light emitting devices interposed between the first substrateand the second substrate; and the glass frit device of claim 1, whereinthe glass frit is interposed between and bonds the first substrate tothe second substrate.
 19. The light emitting device of claim 18, whereinthe light emitting device comprises an organic light emitting diode.